An apparatus and method for cooling in a personal computer including a tilt stand

ABSTRACT

An information processing device including a keyboard for inputting characters or the like, a display for displaying the characters or the like input from the keyboard, a printed wiring board on which electronic components for performing process and display control of the characters or the like input from the keyboard are mounted, and a housing for supporting the keyboard, the display, and the printed wiring board. The information processing device further includes a laterally horizontal shaft supported to a rear portion of the housing, a hollow tilt stand pivotably mounted on the shaft to take a retracted position where the tilt stand is horizontally retracted at a bottom portion of the housing and a raised position where the tilt stand is substantially vertically raised to support the housing in its tilted condition, and a fan provided in the tilt stand. The tilt stand has opposed side walls formed with first ventilation holes. The bottom portion of the housing is formed with second ventilation holes. Heat generated from the electronic components is expelled through the first and second ventilation holes to the outside of the device by the fan.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an information processingdevice, and more particularly to a cooling structure for coolingelectronic components in an information processing device such as anotebook personal computer.

[0003] 2. Description of the Related Art

[0004] With the recent widespread use of a notebook personal computerespecially for improvement in work efficiency, diverse functions havebeen required for the computer to result in high-density mounting ofhigh-integration electronic components having high heating values on aprinted wiring board built in the computer. Furthermore, the requirementfor high-speed operation of a CPU causes an increase in powerconsumption to result in an increase in heating value. Accordingly, itis necessary to efficiently cool such electronic components.

[0005]FIG. 1 is a perspective view of a notebook personal computer as aninformation processing device in the prior art. The notebook personalcomputer shown in FIG. 1 includes a housing 2, a keyboard 6, and adisplay 8 both mounted on the housing 2. Although not shown, a printedwiring board is mounted in the housing 2, and electronic componentsincluding a CPU are mounted on the printed wiring board. A fan 12 forcooling the electronic components is mounted at a rear end portion ofthe housing 2. Further, a tilt stand 14 for adjusting a view angle ofthe display 8 is provided. A plurality of vent holes 4 are formedthrough a front wall of the housing 2 to introduce air into the housing2, and a ventilation hole 10 is formed at the rear end of the housing 2to expel the inside hot air. By driving the fan 12, heat generated fromthe electronic components, especially from the CPU is forcibly expelledto the outside of the housing 2.

[0006] However, a sufficient space cannot be defined between the fan 12and the electronic components in the conventional information processingdevice because of its reduced size and weight. As a result, an efficientventilation space for expelling the heat from the electronic componentscannot be defined, thus hindering ideal heat dissipation.

SUMMARY OF THE INVENTION

[0007] It is therefore an object of the present invention to provide aninformation processing device which can efficiently expel the heat withan increased ventilation space.

[0008] In accordance with an aspect of the present invention, there isprovided an information processing device having electronic componentsand a housing, the information processing device comprising a hollowtilt stand pivotably mounted on a first shaft to take a retractedposition where the tilt stand is horizontally retracted at a bottomportion of the housing and a raised position where the tilt stand issubstantially vertically raised to support the housing in its tiltedcondition; and a fan provided in the tilt stand for expelling heat fromthe electronic components.

[0009] Preferably, the information processing device further comprises afirst terminal connected to a driving section of the fan; a second shaftsupported to the rear portion of the housing; a power supply forsupplying a supply voltage to the electronic components and the drivingportion of said fan; and a switch pivotably mounted on the second shaftand having a second terminal connected to the power supply, the switchbeing rotatable between a first position where the second terminal isseparate from the first terminal in the retracted position of the tiltstand and a second position where the second terminal is kept in contactwith the first terminal by pressure of the tilt stand in the raisedposition thereof.

[0010] Preferably, the information processing device further comprises aprojection formed on the tilt stand; clock switching means having afirst terminal for inputting a first clock signal, a second terminal forinputting a second clock signal, a third terminal for inputting acontrol signal, for outputting to the electronic components one of thefirst clock signal input to the first terminal and the second clocksignal input to the second terminal according to the control signalinput to the third terminal; a second shaft supported to the rearportion of the housing; a power supply for supplying a supply voltage tothe electronic components, the fan, and the clock switching means; and aswitch pivotably mounted on the second shaft and having a fourthterminal connected to the power supply, the switch being rotatablebetween a first position where the switch is separate from theprojection of the tilt stand in the retracted position thereof to makeseparation of the third terminal and the fourth terminal and a secondposition where the switch is in pressure contact with the projection ofthe tilt stand in the raised position thereof to make contact of thethird terminal and the fourth terminal.

[0011] More preferably, the information processing device furthercomprises an extensible partition member elongated over the width of thetilt stand in the lateral direction of the housing, the extensiblepartition member having a front end fixed to the bottom portion of thehousing and a rear end fixed to the tilt stand; wherein when the tiltstand is in the retracted position, the extensible partition member isfolded to fill a gap defined between the bottom portion of the housingand the tilt stand, whereas when the tilt stand is in the raisedposition, the extensible partition member is extended to define anoptimum ventilation space in cooperation with the bottom portion of thehousing and the tilt stand.

[0012] Other objects and features of the invention will be more fullyunderstood from the following detailed description and appended claimswhen taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a perspective view of an information processing devicein the prior art;

[0014]FIG. 2 is a perspective view of an information processing deviceaccording to a preferred embodiment of the present invention;

[0015]FIG. 3 is a cross section taken along the line 3-3 in FIG. 2;

[0016]FIG. 4 is a cross section taken along the line 4-4 in FIG. 3;

[0017]FIGS. 5A and 5B are block diagrams for illustrating the operationof the information processing device shown in FIG. 2; and

[0018]FIG. 6 is a vertical sectional view of an essential part of theinformation processing device shown in FIG. 2, for illustrating theoperation thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A preferred embodiment of the present invention will now bedescribed with reference to the drawings.

[0020]FIG. 2 is a perspective view of an information processing deviceaccording to a preferred embodiment of the present invention. FIG. 3 isa cross section taken along the line 3-3 in FIG. 2. FIG. 4 is a crosssection taken along the line 4-4 in FIG. 3. As shown in FIGS. 2 to 4,the information processing device includes a housing 20, a display 22pivotably supported through a horizontal shaft 25 to the housing 20 atits rear upper portion, a keyboard 24 horizontally supported to thehousing 20, a printed wiring board 30 accommodated in the housing 20, atilt stand 26 pivotably supported through a horizontal shaft 28 to thehousing 20 at its rear lower portion, and an extensible partition member35 connected between the housing 20 and the tilt stand 26. A pluralityof vent holes 23 are formed through a front wall of the housing 20. Aplurality of electronic components 32 including a CPU, a power supply60, and a clock switching element 62 are mounted on the printed wiringboard 30 accommodated in the housing 20. The CPU having a higher heatingvalue in the electronic components 32 is mounted on the lower surface ofthe printed wiring board 30 at its rear portion above the tilt stand 26in its horizontal or retracted position as shown in FIG. 3.

[0021] The housing 20 has a right-angled bottom portion 20 a opposed tothe tilt stand 26 in its retracted position. This bottom portion 20 a ofthe housing 20 is formed with a plurality of ventilation holes 31 suchas slits. The slits may be formed by cutting a sheet metal or plastic.The tilt stand 26 is a laterally elongated, hollow boxlike member havingopposed side walls formed with a plurality of ventilation holes 27 suchas slits. The tilt stand 26 is rotatable about 90 degrees about thehorizontal shaft 28 supported to the housing 20. A stopper 38 projectsinward from a rear wall of the housing 20, so as to maintain asubstantially vertical or raised position of the tilt stand 26. Aprojection 36 is formed at a rear end of the tilt stand 26 in itsretracted position so as to project toward the rear wall of the housing20. A fan 34 is provided in the tilt stand 26.

[0022] The fan 34 is constructed as a single fan unit consisting of adriving section and a rotating blade section integrated together, andthis single fan unit is located at a substantially central position inthe tilt stand 26. Alternatively, a plurality of fans may be provided inthe tilt stand 26, or the driving section and the rotating blade sectionmay be separated. The extensible partition member 35 is a laterallyelongated, bellowslike member normally folded in the longitudinaldirection of the housing 20 and connected between the housing 20 and thetilt stand 26 to fill a gap defined therebetween. That is, theextensible partition member 35 has a front end fixed to a vertical wallof the right-angled bottom portion 20 a of the housing 20 and a rear endfixed to a front end of the tilt stand 26 in its retracted position. Inthe retracted position of the tilt stand 26, the partition member 35 isfolded in the gap between the vertical wall of the bottom portion 20 aof the housing 20 and the front end of the tilt stand 26.

[0023] In the raised position of the tilt stand 26 as shown in FIG. 6,there is defined an optimum ventilation space S by the tilt stand 26,the partition member 35, and the housing 20 by the extension of thepartition member 35. The partition member 35 is formed of any extensiblematerial such as plastics. If the partition member 35 is not provided, alarger ventilation space is defined by the tilt stand 26, the housing20, and a desk on which the device is placed in the raised position ofthe tilt stand 26, so that heat from the electronic components 32 may bediffused to an extra area of the ventilation space, and accordinglythere is a possibility that the heat cannot be enough expelled by thefan 34. By determining an optimum mounting position of the partitionmember 35 in consideration of the capacity of the fan 34, etc., theoptimum ventilation space S can be defined. A switch 40 is pivotablymounted on a horizontal shaft 44 supported to the housing 20. In theretracted position of the tilt stand 26, the switch 40 is separate fromthe projection 36 of the tilt stand 26. In the raised position of thetilt stand 26, the switch 40 is in contact with the projection 36. Inraising the tilt stand 26, the projection 36 comes into contact with theswitch 40 and rotates the switch 40 about the shaft 44 clockwise asviewed in FIG. 3.

[0024] A spring 42 is wound around the shaft 44 and supported to a lowerprojection 46 and an upper projection 48 of the switch 40. The switch 40has a terminal 50 formed of conductor at an upper position. In theretracted position of the tilt stand 26, the terminal 50 of the switch40 is separate from a terminal 58 supported to the housing 20. In theraised position of the tilt stand 26, the terminal 50 of the switch 40is in contact with the terminal 58 of the housing 20. A wire 52 isconnected at its one end to the terminal 50 and connected at the otherend to the power supply 60. On the other hand, a wire 54 is connected atits one end to the terminal 58 and connected at the other end to a clockswitching element 62, and a wire 56 is connected at its one end to theterminal 58 and connected at the other end to the driving section (notshown) of the fan 34. The power supply 60 functions to supply a supplyvoltage from a battery (not shown) accommodated in the housing 20 orfrom an adapter (not shown) for converting a commercial AC voltage intoa DC voltage, to the electronic components 32, the clock switchingelement 62, and the driving section of the fan 34. The clock switchingelement 62 receives a high-speed clock signal CLK1 having a frequency of100 MHz, for example, and a low-speed clock signal CLK2 having afrequency of 50 MHz, for example from a clock generating circuit (notshown), and further receives a control signal for a supply voltage or aground potential from the switch 40. When the potential of the controlsignal is equal to the supply voltage, the clock switching element 62supplies the high-speed clock signal CLK1 to the electronic components32, whereas when the potential of the control signal is equal to theground potential, the clock switching element 62 supplies the low-speedclock signal CLK2 to the electronic components 32.

[0025]FIGS. 5A, 5B, and 6 illustrate the operation of the informationprocessing device shown in FIG. 2. The operation of the informationprocessing device shown in FIG. 2 will now be described with referenceto these figures.

[0026] (a) Operation in the raised position of the tilt stand 26:

[0027] In the case of using the device in the raised position of thetilt stand 26, the adapter is used in general. In this case, acommercial AC voltage is converted into a DC voltage by the adapter, andthe DC voltage is supplied as a supply voltage from the power supply 60to the electronic components 32, the clock switching element 62, and thefan 34. The tilt stand 26 is rotated about the shaft 28 counterclockwiseas viewed in FIG. 3 by a user until the tilt stand 26 abuts against thestopper 38 as shown in FIG. 6. Accordingly, the tilt stand 26 issupported in a substantially vertical position by the stopper 38 andplaced on a desk 70 or the like. At the same time, the folded partitionmember 35 is extended by the rotation of the tilt stand 26 as shown inFIG. 6, thereby defining the optimum ventilation space S among thepartition member 35, the tilt stand 26, and the right-angled bottomportion 20 a of the housing 20.

[0028] Further, the projection 36 of the tilt stand 26 rotatescounterclockwise and comes into contact with the lower projection 46 ofthe switch 40 to press the switch 40 and rotate it about the shaft 44clockwise as viewed in FIG. 6 against the biasing force of the spring42. As a result, the terminal 50 of the switch 40 comes into contactwith the terminal 58 as shown in FIGS. 5A and 6, thereby supplying thesupply voltage from the power supply 60 to the terminal 58. Because theterminal 58 is connected through the wire 54 to a terminal for inputtingthe control signal for the clock switching element 62 and also connectedthrough the wire 56 to the driving section of the fan 34, the potentialof the control signal for the clock switching element 62 becomes equalto the supply voltage from the power supply 60, and the clock switchingelement 62 supplies the high-speed clock signal CLK1 to the electroniccomponents 32. Accordingly, the CPU is operated by the high-speed clocksignal CLK1. Further, the supply voltage is supplied to the drivingsection of the fan 34 to operate the fan 34. On the other hand, the heatgenerated from the electronic components 32 including the CPU operatedby the high-speed clock signal CLK1 is relieved through the ventilationholes 31 of the bottom portion 20a of the housing 20 into theventilation space S. The heat in the ventilation space S is nextexpelled through the ventilation holes 27 of the tilt stand 26 to theoutside of the device by the operation of the fan 34, thereby coolingthe electronic components 32. The ventilation space S is optimallyformed, and the CPU having a higher heating value in the electroniccomponents 32 is located near the ventilation holes 31. Accordingly, theheat generated from the electronic components 32 can be efficientlyrelieved to the ventilation space S.

[0029] (b) Operation in the retracted position of the tilt stand 26:

[0030] In the case of using the device in the retracted position of thetilt stand 26, the battery is often used as a power source without usingthe adapter, and the device is used on the user's lap, for example. Inretracting the tilt stand 26 from the raised position shown in FIG. 6,the tilt stand 26 is rotated clockwise as viewed in FIG. 6 by thebiasing force of the spring 42. As a result, the projection 36 of thetilt stand 26 is separated from the switch 40, and the terminal 50 ofthe switch 40 is also separated from the terminal 58 as shown in FIGS. 3and 5B. Accordingly, the potentials at the wire 54 and the terminal 58become equal to a ground potential, so that the potential of the controlsignal for the clock switching element 62 becomes equal to a groundpotential, and the clock switching element 62 supplies the low-speedclock signal CLK2 to the electronic components 32.

[0031] As a result, the CPU is operated at a low speed, therebysuppressing current consumption and heat generation. Accordingly,although the device is used on the user's lap, possible low-temperatureburn to the user due to the heat expelled from the device can besuppressed. Further, because the potential at the wire 56 also becomesequal to a ground potential, the fan 34 is not driven, therebyeliminating power consumption of the battery due to the operation of thefan 34.

[0032] As described above, the fan 34 is provided in the tilt stand 26having the ventilation holes 27. In the raised position of the tiltstand 26, the CPU is operated at a high speed, and the fan 34 is drivento forcibly expel the heat from the CPU through the sufficientventilation space S to the outside of the device, thereby efficientlycooling the CPU. On the other hand, in the retracted position of thetilt stand 26, the CPU is operated at a low speed to suppress heatgeneration from the CPU, thereby suppressing the occurrence oflow-temperature burn in the case of using the device on the user's lap.

[0033] According to the present invention, a sufficient ventilationspace can be defined in the raised position of the tilt stand 26, andthe heat generated from the electronic components can be efficientlyexpelled through the ventilation space by the fan built in the tiltstand.

What is claimed is:
 1. An information processing device havingelectronic components and a housing, said information processing devicecomprising: a hollow tilt stand pivotably mounted on a first shaft totake a retracted position where said tilt stand is horizontallyretracted at a bottom portion of said housing and a raised positionwhere said tilt stand is substantially vertically raised to support saidhousing in its tilted condition; and a fan provided in said tilt standfor expelling heat from said electronic components.
 2. An informationprocessing device according to claim 1, wherein said tilt stand hasopposed side walls formed with first ventilation holes.
 3. Aninformation processing device according to claim 1, wherein said firstshaft horizontally extends in a lateral direction of said housing andsupported to a rear portion of said housing.
 4. An informationprocessing device according to claim 1, wherein said bottom portion ofsaid housing is formed with second ventilation holes for allowing passof said heat from said electronic components.
 5. An informationprocessing device according to claim 1, further comprising: a firstterminal connected to a driving section of said fan; a second shaftsupported to said rear portion of said housing; a power supply forsupplying a supply voltage to said electronic components and saiddriving portion of said fan; and a switch pivotably mounted on saidsecond shaft and having a second terminal connected to said powersupply, said switch being rotatable between a first position where saidsecond terminal is separate from said first terminal in said retractedposition of said tilt stand and a second position where said secondterminal is kept in contact with said first terminal by pressure of saidtilt stand in said raised position thereof.
 6. An information processingdevice according to claim 1, further comprising: a projection formed onsaid tilt stand; a first terminal connected to a driving section of saidfan; a second shaft supported to said rear portion of said housing; apower supply for supplying a supply voltage to said electroniccomponents and said driving portion of said fan; and a switch pivotablymounted on said second shaft and having a second terminal connected tosaid power supply, said switch being rotatable between a first positionwhere said switch is separate from said projection of said tilt stand insaid retracted position thereof to make separation of said firstterminal and said second terminal and a second position where saidswitch is in pressure contact with said projection of said tilt stand insaid raised position thereof to make contact of said first terminal andsaid second terminal.
 7. An information processing device according toclaim 1, further comprising: clock switching means having a firstterminal for inputting a first clock signal, a second terminal forinputting a second clock signal, and a third terminal for inputting acontrol signal, for outputting to said electronic components one of saidfirst clock signal input to said first terminal and said second clocksignal input to said second terminal according to said control signalinput to said third terminal; a second shaft supported to said rearportion of said housing; a power supply for supplying a supply voltageto said electronic components, said fan, and said clock switching means;and a switch pivotably mounted on said second shaft and having a fourthterminal connected to said power supply, said switch being rotatablebetween a first position where said fourth terminal is separate fromsaid third terminal in said retracted position of said tilt stand and asecond position where said fourth terminal is kept in contact with saidthird terminal by pressure of said tilt stand in said raised positionthereof.
 8. An information processing device according to claim 1,further comprising: a projection formed on said tilt stand; clockswitching means having a first terminal for inputting a first clocksignal, a second terminal for inputting a second clock signal, a thirdterminal for inputting a control signal, for outputting to saidelectronic components one of said first clock signal input to said firstterminal and said second clock signal input to said second terminalaccording to said control signal input to said third terminal; a secondshaft supported to said rear portion of said housing; a power supply forsupplying a supply voltage to said electronic components, said fan, andsaid clock switching means; and a switch pivotably mounted on saidsecond shaft and having a fourth terminal connected to said powersupply, said switch being rotatable between a first position where saidswitch is separate from said projection of said tilt stand in saidretracted position thereof to make separation of said third terminal andsaid fourth terminal and a second position where said switch is inpressure contact with said projection of said tilt stand in said raisedposition thereof to make contact of said third terminal and said fourthterminal.
 9. An information processing device according to claim 1,further comprising: an extensible partition member elongated over thewidth of said tilt stand in the lateral direction of said housing, saidextensible partition member having a front end fixed to said bottomportion of said housing and a rear end fixed to said tilt stand; whereinwhen said tilt stand is in said retracted position, said extensiblepartition member is folded to fill a gap defined between said bottomportion of said housing and said tilt stand, whereas when said tiltstand is in said raised position, said extensible partition member isextended to define an optimum ventilation space in cooperation with saidbottom portion of said housing and said tilt stand.